Systems, methods and computer-accessible medium which provide microscopic images of at least one anatomical structure at a particular resolution

ABSTRACT

Exemplary embodiments of apparatus, systems and methods can be provided for providing at least one electro-magnetic radiation to at least one sample. For example, a plurality of wave-guiding arrangements can be provided which are configured to (i) provide the electro-magnetic radiation(s), and (ii) at a point of emission of each of the wave guiding arrangements, cause a phase of each of the electro-magnetic radiation(s) to have a predetermined value. The exemplary apparatus can be part of a probe. Further the exemplary apparatus can include an interferometric arrangement provided in communication with the probe and/or be part of the probe.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based upon and claims the benefit of priority fromU.S. Patent Application Ser. Nos. 61/311,171 and 61/311,272, both filedMar. 5, 2010, the entire disclosures of which are incorporated herein byreference.

FIELD OF THE DISCLOSURE

The present disclosure relates to exemplary embodiments of imagingsystems, apparatus and methods, and more specifically to methods,systems and computer-accessible medium which provide microscopic imagesof at least one anatomical structure at a particular resolution.

BACKGROUND INFORMATION

Coronary artery disease (CAD) and its clinical manifestations, includingheart attack or acute myocardial infarction (AMI), is the number onecause of mortality in the US, claiming nearly 500,000 lives and costingapproximately $400B per year. Topics relevant to the pathophysiology ofCAD, such as the development and progression of coronary atheroscleroticlesions, plaque rupture and coronary thrombosis, and the arterialresponse to coronary device and pharmacologic therapies are therefore ofgreat significance today. These biological processes can be mediated bymolecular and cellular events that occur on a microscopic scale. Certainprogress in understanding, diagnosing, and treating CAD has beenhindered by the fact that it has been difficult or impossible tointerrogate the human coronary wall at cellular-level resolution invivo.

Over the past decade, intracoronary optical coherence tomography (OCT)has been developed, which is a catheter-based technique that obtainscross-sectional images of reflected light from the coronary wall.Intracoronary OCT has a spatial resolution of 10 μm, which is an orderof magnitude better than that of the preceding coronary imaging method,intravascular ultrasound (IVUS). In the parent R01, a second-generationform of OCT has been developed, i.e., termed optical frequency domainimaging (OFDI), that has very high image acquisition rates, making itpossible to conduct high-resolution, three-dimensional imaging of thecoronary vessels. In addition, a flushing method has been developedwhich, in combination with the high frame rate of OFDI, can overcome atleast some of the obstacles of blood interference with the OCT signal.As a direct result, it may be preferable to perform intracoronary OCTprocedures in the clinical setting. Indeed, certain interventionalcardiology applications for OCT have emerged, and growing the fieldexponentially. It is believed that OCT can become a significant imagingmodality for guiding coronary interventions worldwide.

Since the technology developed in the parent R01 has been translated andfacilitated for a clinical practice through the distribution ofcommercial OFDI imaging systems, it may be preferable to reviewmacromolecules and cells involved in the pathogenesis of CAD.

For example, a transverse resolution in OCT procedure(s) can bedetermined by the catheter's focal spot size. To improve the resolution,it is possible to increase the numerical aperture of the lens thatfocuses light into the sample. This conventional method, however,neglects the intrinsic compromise between transverse resolution anddepth of field in cross-sectional OCT images and results in images inwhich only a narrow depth range is resolved.

An alternative approach can exploit the unique characteristics ofBessel, or “non-diffracting” beams to produce high transverse resolutionover enhanced depths-of-field. Bessel beam illumination and detection oflight reflected from the sample, however, can suffer from a significantreduction in contrast and detection efficiency. Thus, there may be aneed to overcome at least some of the deficiencies associated with theconventional arrangements and methods described above.

As briefly indicated herein above, certain exemplary embodiments of thepresent disclosure can be associated and/or utilize analysis andmanipulation of a coherent transfer function (CTF) of an exemplary OCTsystem. The current invention is instead based on an analysis andmanipulation of the coherent transfer function (CTF) of an OCT system.The CTF can be considered a coherent extension of a modulation transferfunction (MTF) and an optical transfer function (OTF). Thus, forexample, for non-interferometric systems, the MTF or OTF can bemanipulated and utilized according to certain exemplary embodiments. Ingeneral, the quality of an optical system can be assessed by comparingits transfer function to that of a diffraction-limited optical system.FIG. 1 shows a graph of coherent transfer functions (CTFs) for, e.g., adiffraction limited 2.5 μm diameter spot and 2.5 μm spot with anextended focal range of 2.0 mm, produced by Bessel beam illumination anddetection. As illustrated in FIG. 1, the transfer function of a Besselbeam illumination and detection 100 can have spatial frequencies thatexceed a diffraction-limited system 110, although it likely sacrificeslow- and mid-range spatial frequencies, possibly resulting in reducedcontrast and detection sensitivity.

Thus, there may be a need to overcome at least some of the deficienciesassociated with the conventional arrangements and methods describedabove.

SUMMARY OF EXEMPLARY EMBODIMENTS OF THE DISCLOSURE

To address and/or overcome such deficiencies, one of the objects of thepresent disclosure is to provide exemplary embodiments of systems,methods and computer-accessible medium according to the presentdisclosure, which can provide microscopic images of at least oneanatomical structure at a particular resolution. Another object of thepresent disclosure is to overcome a limited depth of focus limitationsof conventional Gaussian beam and spatial frequency loss of Bessel beamsystems for OCT procedures and/or systems and other forms of extendedfocal depth imaging.

According to another exemplary embodiment of the present disclosure,more than two imaging channels can illuminate/detect different Besseland/or Gaussian beams. In yet a further exemplary embodiment, differenttransfer functions can be illuminated and/or detected. The exemplarycombination of images obtained with such additional exemplary beams canfacilitate the μOCT CTF to be provided to the diffraction-limited case,and can also facilitate a depth-of-field extension even further.

Accordingly, exemplary embodiments of apparatus, systems and methods canbe provided for providing at least one electro-magnetic radiation to atleast one sample. For example, a plurality of wave-guiding arrangementscan be provided which are configured to (i) provide the electro-magneticradiation(s), and (ii) at a point of emission of each of the waveguiding arrangements, cause a phase of each of the electro-magneticradiation(s) to have a predetermined value. The exemplary apparatus canbe part of a probe. Further the exemplary apparatus can include aninterferometric arrangement provided in communication with the probeand/or be part of the probe.

In another exemplary embodiment of the present disclosure, thewave-guiding arrangements can provide the radiation(s) in at leastpartially a circular pattern. At least one lens arrangement can beincluded which is configured to receive the electro-magneticradiation(s) from the wave-guiding arrangements, and generate a furtherfocus-spot radiation. The lens arrangement(s) can be configured to causethe further focus-spot radiation to have (i) an extended focal depth,and/or (ii) a diameter that is smaller than a diffraction limited spoton or in the sample. The diffraction limited spot can be athree-dimensional spot. In addition or alternatively, The lensarrangement(s) can include a grin lens.

According to yet another exemplary embodiment of the present disclosure,at least one of the wave-guiding arrangements can be (i) a single-modewave-guide, and/or (ii) composed a photo-polymer. Additionally, afurther wave-guiding arrangement can be provided, which is configured toprovide a further electro-magnetic radiation to the sample, where theelectro-magnetic radiation(s) and the further electro-magnetic radiationcan be provided to at least partially overlapping portions of thesample. A housing can also be provided which at least partially enclosesthe wave-guiding arrangements, and/or a sheath can be provided whichencloses the housing. Further, a control arrangement can be providedwhich is configured to rotate and/or translate the housing. The lensarrangement(s) can include at least one optical element formed by and/orsubjected to a photopolymer processing. The photopolymer processing caninclude irradiating a photopolymer so as to form the optical element(s).

In a further exemplary embodiment of the present disclosure, method andsystem can be provided for generating data associated with at least oneportion of a sample. For example, at least one first radiation can beforwarded to the portion(s) of the sample through at least one opticalarrangement which is formed by or subjected to a photopolymerprocessing. At least one second radiation can be received from theportion(s) which can be based on the first radiation(s). Based on aninteraction between the optical arrangement(s) and the first radiationand/or the second radiation, the optical arrangement can have a firsttransfer function. Then, at least one third radiation can be forwardedto the portion(s) through the optical arrangement. At least one fourthradiation can be received from the portion(s) which can be based on thethird radiation(s). Based on an interaction between the opticalarrangement(s) and the third radiation and/or the fourth radiation, theoptical arrangement(s) can have a second transfer function, where thefirst transfer function can be at least partially different from thesecond transfer function. Further, the data associated with theportion(s) can be generated based on the second and fourth radiations.

According to yet further exemplary embodiment of the present disclosure,method and system can be provided also for generating data associatedwith at least one portion of a sample. For example, at least one firstradiation can be forwarded to the portion(s) of the sample through atleast one first optical arrangement which is formed by or subjected to aphotopolymer processing. At least one second radiation can be receivedfrom the portion(s) which can be based on the first radiation(s). Basedon an interaction between the first optical arrangement(s) and the firstradiation and/or the second radiation, the first optical arrangement(s)can have a first transfer function. Then, at least one third radiationcan be forwarded to the portion(s) through at least one second opticalarrangement. At least one fourth radiation can be received from theportion(s) which can be based on the third radiation(s). Based on aninteraction between the second optical arrangement(s) and the thirdradiation and/or the fourth radiation, the second optical arrangement(s)can have a second transfer function, where the first transfer functioncan be at least partially different from the second transfer function.Further, the data associated with the portion(s) can be generated basedon the second and fourth radiations. The first optical arrangement(s)and/or the second optical arrangement(s) can be formed by or subjectedto a photopolymer processing.

These and other objects, features and advantages of the exemplaryembodiment of the present disclosure will become apparent upon readingthe following detailed description of the exemplary embodiments of thepresent disclosure, when taken in conjunction with the appended claims.

BRIEF DESCRIPTION OF THE DRAWING(S)

Further objects, features and advantages of the present invention willbecome apparent from the following detailed description taken inconjunction with the accompanying figures showing illustrativeembodiments of the present disclosure, in which:

FIG. 1 is an exemplary graph of coherent transfer functions (CTFs) as afunction of spatial frequencies produced by the prior Bessel beamillumination and detection;

FIG. 2 is an exemplary graph of coherent transfer functions (CTFs) as afunction of spatial frequencies produced by an exemplary embodiment of aprocedure and/or technique according to the present disclosure;

FIG. 3A is a first exemplary OCT image an exemplary OCT image of acadaver coronary artery plaque obtained using an exemplaryprocedure/techniques according to an exemplary embodiment of the presentdisclosure, whereas an exemplary Gauss-Gauss image contains low spatialfrequency information;

FIG. 3B is a second exemplary OCT image of the cadaver coronary arteryplaque using an exemplary procedure/techniques according to an exemplaryembodiment of the present disclosure, whereas an exemplary Bessel-Besselimage provides high-resolution but loses low and mid spatialfrequencies;

FIG. 3C is a third exemplary OCT image of the cadaver coronary arteryplaque using an exemplary procedure/techniques according to an exemplaryembodiment of the present disclosure, which provides a combined μOCTimage (e.g., Gauss-Gauss+Gauss-Bessel+Bessel-Bessel), and images arenormalized and displayed with the same brightness/contrast values;

FIG. 4A is a side cut-away view of a diagram of distal optics of a OCTcatheter system according to an exemplary embodiment of the presentdisclosure;

FIG. 4B is an exemplary graph of a polymer index profile generated usinga Y-junction fan-out of the system the exemplary embodiment of shown inFIG. 4A;

FIG. 4C is an exemplary graph of an illumination profile generated usingthe Y-junction fan-out of the system the exemplary embodiment of shownin FIG. 4A;

FIG. 4D is an exemplary graph of an simulated x-z PSF using theY-junction fan-out of the system the exemplary embodiment of shown inFIG. 4A;

FIG. 5A is a side cut-away view of a diagram of the distal optics of aOCT catheter system according to another exemplary embodiment of thepresent disclosure;

FIG. 5B is an exemplary graph of an illumination profile generated usingthe distal optics con figuration of the system the exemplary embodimentof shown in FIG. 5A;

FIG. 5C is an exemplary graph of simulated x-z PSF generated using thedistal optics con figuration of the system the exemplary embodiment ofshown in FIG. 5A;

FIG. 6 is a schematic diagram of a system for generating one or moreμOCT images according to still a further exemplary embodiment of thepresent disclosure;

FIG. 7 are side cut-away views of diagrams of the distal optics of theOCT catheter system according to still another exemplary embodiment ofthe present disclosure which includes axicon pair and a routing of aring beam and a Gaussian beam of the distal optics configuration;

FIG. 8 is a side cut-away view of a diagram of the OCT catheter systemaccording to yet further exemplary embodiment of the present disclosurewhich includes an exemplary optical pathlength incoding probeconfiguration that uses a single fiber and a single axicon lens;

FIG. 9 are side cut-away views of diagrams of the OCT catheter systemaccording to a still further exemplary embodiment of the presentdisclosure which includes a further exemplary optical pathlengthincoding probe configuration that uses a single fiber and a singleaxicon lens;

FIG. 10 are schematic views of diagrams of the distal optics of the OCTcatheter system according to a further exemplary embodiment of thepresent disclosure which includes a single fiber multifocal lens probeconfiguration;

FIG. 11 is a side cut-away view of a diagram of the OCT catheter systemaccording to a still further exemplary embodiment of the presentdisclosure which utilizes a mirror tunnel;

FIG. 12 is a side cut-away view of a diagram a portion of the OCTcatheter system according to yet another exemplary embodiment of thepresent disclosure which utilizes a reflective achromatic phase mask anda ball lens;

FIG. 13 is a graph of a phase shift spectra of chromatic light uponreflection at glass-metal interface based on the exemplary embodiment ofFIG. 12;

FIG. 14A is an illustration of a Huygens diffraction pattern of lenswith conventional focusing;

FIG. 14B is an exemplary illustration of a Huygens diffraction patternof lens with reflective achromatic phase mask and ball lens depicted inthe exemplary embodiment of the system illustrated in FIG. 13.

FIG. 15A is a schematic diagram of an exemplary embodiment of a focusingarrangement that uses a refractive achromatic phase doublet mask inaccordance with an exemplary embodiment of the present disclosure;

FIG. 15B is an exemplary graph of transverse phase profiles of anexemplary mask illustrated in FIG. 15A;

FIG. 16 is a schematic diagram of the OCT system which includes awavefront beam splitter and a common path interferometer, according toyet another exemplary embodiment of the present disclosure;

FIG. 17A is an exemplary simulated PSF illustration of generated by theexemplary OCT system shown in FIG. 16 that uses a monochromatic lightsource (e.g., λ=825 nm) and a spherical aberration free objective lens;

FIG. 17B is an exemplary simulated PSF illustration of generated by theexemplary OCT system shown in FIG. 16 that uses a monochromatic lightsource (e.g., λ=825 nm) and an objective lens with a sphericalaberration and a wavelength dependent focal shift;

FIG. 17C is an exemplary simulated PSF illustration of generated by theexemplary OCT system shown in FIG. 16 that uses a broadband source(e.g., about 600 nm to 1050 nm) and an objective lens with sphericalaberration and a wavelength dependent focal shift;

FIG. 17D is an exemplary simulated PSF illustration of generated by theexemplary OCT system shown in FIG. 16 that uses broadband source (e.g.,600 nm to 1050 nm), an objective lens with spherical aberration and awavelength dependent focal shift, and an wavefront beam splitter;

FIG. 18A is an exemplary μOCT image of a coronary plaque showingmultiple leukocytes (arrows);

FIG. 18B is an exemplary μOCT image of a coronary plaque illustratingmultiple leukocytes (arrows) of two different cell types, one smallercell with scant cytoplasm, consistent with a lymphocyte (L) and another,larger cell with a highly scattering cytoplasm, indicative of a monocyte(M);

FIG. 18C is an exemplary μOCT image of a coronary plaque illustrating acell with an indented, bean-shaped nucleus (M) characteristic of amonocyte;

FIG. 18D is an exemplary μOCT image of a coronary plaque illustrating aleukocyte with a multi-lobed nucleus, which can indicate a neutrophil(N) attached to the endothelial surface;

FIG. 18E is an exemplary μOCT image of the coronary plaque illustratingmultiple leukocytes tethered to the endothelial surface by pseudopodia;

FIG. 18F is an exemplary μOCT image of the coronary plaque illustratingcells with the morphology of monocytes (M) in a cross-section and aninset transmigrating through the endothelium;

FIG. 18G is an exemplary μOCT image of multiple leukocytes distributedon the endothelial surface;

FIG. 19A is an exemplary μOCT image of platelets (P) adjacent to aleukocyte characteristic of a neutrophil (N), which is also attached toa small platelet;

FIG. 19B is an exemplary μOCT image of fibrin (F) which is visible aslinear strands bridging a gap in the coronary artery wall;

FIG. 19C is an exemplary μOCT image of a cluster of leukocytes (L),adherent to the fibrin in an adjacent site to that illustrated in FIG.19B;

FIG. 19D is an exemplary μOCT image of Fibrin thrombus (T) withmultiple, entrapped leukocytes;

FIG. 19E is an exemplary μOCT image of a more advanced thrombus (T)showing a leukocyte and fibrin strands;

FIG. 20A is a cross-sectional exemplary μOCT image of endothelial cellsin culture;

FIG. 20B is an en face exemplary μOCT image of endothelial cells inculture;

FIG. 20C is an exemplary μOCT image of a native swine coronary arterycross-section;

FIG. 20D is an exemplary three-dimensional rendering of the swinecoronary artery, demonstrating endothelial “pavementing”;

FIG. 21A is an exemplary μOCT image of microcalcifications which can beseen as bright densities within the μOCT image of the fibrous cap;

FIG. 21B is an exemplary μOCT image of the microcalcifications which canbe seen as dark densities on the corresponding histology;

FIG. 22A is an exemplary μOCT image of a large calcium nodule,demonstrating disrupted intima/endothelium;

FIG. 22B is an expanded view of the region enclosed by a boxillustrating microscopic tissue strands, consistent with fibrin (F),adjoining the unprotected calcium (white arrow) to the opposing detachedintima;

FIG. 22C is an illustration of a corresponding histology of fibrin (F,black arrows) and denuded calcific surface (gray arrow);

FIG. 23A is an exemplary μOCT image of a large necrotic core (NC)fibroatheroma, demonstrating thick cholesterol crystals (CC),characterized by reflections from their top and bottom surfaces;

FIG. 23B is an exemplary μOCT image of thin crystal (CC, gray arrow)piercing the cap of another necrotic core plaque (NC), shown in moredetail in the inset;

FIG. 24A is an exemplary μOCT image of various smooth muscle cellsappearing as low backscattering spindle-shaped cells (inset);

FIG. 24B is an exemplary μOCT image of smooth muscle cells producingcollagen are spindle shaped, have a high backscattering interior (lightgray arrow) and a “halo” of low backscattering (white arrow), whichrepresents the cell body and collagen matrix, respectively (histologyinset);

FIG. 25A is an exemplary μOCT image of Taxus Liberte struts with/withoutpolymer/drug, i.e., for polymer-coated struts, polymer reflection (PR),strut reflection (SR) and multiple reflections (MR1, MR2) can be seen;

FIG. 25B is an exemplary μOCT image of a cadaver coronary specimen withan implanted BMS shows struts devoid of polymer, covered by neointima;

FIG. 25C is an exemplary μOCT image of a cadaver coronary specimen withimplanted DES struts from another cadaver showing polymer overlying thestrut reflections (P, inset);

FIG. 26A is an exemplary μOCT image showing tissue (light gray arrow)has separated the polymer off of the stent strut and the polymer hasfractured (white arrow);

FIG. 26B is an exemplary μOCT image illustrating a superficial leukocytecluster (red arrow) and adjacent attached leukocytes overlying the siteof the polymer fracture;

FIG. 26C is an exemplary μOCT image illustrating an inflammation at theedge of a strut (dashed region) from another patient;

FIG. 26D is an exemplary μOCT image illustrating an uncovered strut,completely devoid of overlying endothelium (inset);

FIG. 27A is a flow diagram of a process according to one exemplaryembodiment of the present disclosure; and

FIG. 27B is a flow diagram of the process according to another exemplaryembodiment of the present disclosure.

Throughout the figures, the same reference numerals and characters,unless otherwise stated, are used to denote like features, elements,components or portions of the illustrated embodiments. Moreover, whilethe subject disclosure will now be described in detail with reference tothe figures, it is done so in connection with the illustrativeembodiments. It is intended that changes and modifications can be madeto the described exemplary embodiments without departing from the truescope and spirit of the subject disclosure as defined by the appendedclaims.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

According to one exemplary embodiment of the present disclosure, two ormore imaging channels can be utilized, e.g., at least one whichproviding the Bessel beam illumination or detection and at least anotherone of which providing a Gaussian beam illumination or detection. Thisexemplary configuration can facilitate three or more unique andseparable illumination-detection combinations (e.g., Bessel-Bessel,Bessel-Gaussian, Gaussian-Gaussian, etc.), where each combination cancorrespond to a different OCT image. As shown in the exemplary graph ofFIG. 2, coherent transfer functions (CTFs) for 2.5 μm diameter spots areprovided.

For example, FIG. 2 illustrates a graphical comparison of a diffractionlimit 200, extended focal range of 0.15 mm used in preliminary data 210,and the exemplary results of an exemplary embodiment of a procedure ortechnique according to the present disclosure, hereinafter termed μOCT,with a focal range of 2.0 mm. According to one exemplary embodiment ofthe present disclosure he μOCT CTF can be generated, e.g., by combiningGaussian-Gaussian images 220, Bessel-Gaussian images 230, andBessel-Bessel images 240.

In another exemplary embodiment of the present disclosure, the exemplaryμOCT CTF procedure/technique can be used and/or provided over an axialfocus range that can be, e.g., more than 0.5 mm, 1 mm, 2 mm, etc. (aswell as others). According to additional exemplary embodiments of thepresent disclosure, the transverse FWHM spot diameters can be less than5 μm, 2 μm, 1 μm, etc. (as well as others). In still further exemplaryembodiments of the present disclosure, the depth of focus can beextended a factor of, e.g., approximately 2, 5, 10, 20, 50, 100, etc.(and possibly more) compared to the illumination with a plane wave orGaussian beam. In yet another exemplary embodiment of the presentdisclosure, the high, low, and medium spatial frequency content in theimage can be at least partially restored by combining images withdifferent transfer functions.

FIGS. 3A-3C show exemplary OCT images of a cadaver coronary arteryplaque obtained using an exemplary procedure/techniques according toexemplary embodiments of the present disclosure. For example, in FIG. 3Aan exemplary Gauss-Gauss image contains low spatial frequencyinformation. In FIG. 3B, an exemplary Bessel-Bessel image provideshigh-resolution but loses low and mid spatial frequencies. Further, inFIG. 3C, a combined μOCT image (e.g.,Gauss-Gauss+Gauss-Bessel+Bessel-Bessel) is provided, and images arenormalized and displayed with the same brightness/contrast values.

FIG. 4A shows a side cut-away view of a diagram of a system whichincludes distal optics of a OCT catheter according to a first exemplaryembodiment of the present disclosure. This exemplary system includes aY-junction fan-out to produce the annulus (e.g., a darker shade in FIG.4A) and the Gaussian beam (e.g., a lighter shade in FIG. 4A) of anexemplary distal optics design and/or configuration. This exemplarysystem of FIG. 4A is provided to generate a diffraction-limited CTF andan axial focus range (e.g., a depth-of-focus) that can be more than,e.g., about 10 times longer than the diffraction-limited depth-of-focus.As shown in FIG. 4A, an exemplary output of a waveguide 400 can betransformed by a y-junction fan-out element 410 to an array of spotsthat subtend a pattern such as a circle (as shown in an illustration ofFIG. 4C). The index profile of this element (as shown in an exemplarygraph of FIG. 4B) can be configured to be lossless and achromatic. Theoutput of each spot can be individually collimated by a beam collimatorin a collimator array 420.

As show in FIG. 4A, a Gaussian beam can be routed through a separatewaveguide 430 in the center of the annular array. The exemplary outputof the waveguide can be collimated by a collimator 440 located in thecenter of the collimator array 420. Exemplary collimated annular andGaussian beams can be focused onto the sample using, e.g., one or morelenses, including but not limited to a gradient index (GRIN) lens 450,as shown in FIG. 4A. In addition to focusing two beams, such exemplaryGRIN lens(es) 450 can be configured and/or structured to intentionallygenerate chromatic aberration, which can extend the axial focus yetfurther (as shown in an illustration of FIG. 4D), and to possiblycompensate for the aberrations induced by a transparent outer sheath460. Electro-magnetic radiation (e.g., light) can be directed to ananatomical structure 480 by a deflector 470.

FIG. 5A shows a second exemplary embodiment of distal optics of a OCTcatheter system according to the present disclosure. For example, theexemplary system of FIG. 5A illustrates an axicon arrangement (e.g.,pair) and a routing of the annulus (shown in a darker shade in FIG. 5A)and the Gaussian beam (shown in a lighter shade in FIG. 5A) of thedistal optics design according to this exemplary embodiment. Inparticular, the exemplary system illustrate din FIG. 5A can generate adiffraction-limited CTF and an axial focus range (e.g., depth-of-focus)that can be more than, e.g., 10 times longer than thediffraction-limited depth-of-focus. The output of a waveguide 500 can becollimated by a collimator 510 located in a center of the exemplarycatheter system. The collimated electro-magnetic radiation (e.g., light)can be transformed into an annular beam using two or more axicons 520,530. According to another exemplary embodiment, the axicons can begenerated or produced using gradient index.

As shown in FIG. 5A, a separate waveguide540 can be routed through thecenter of the annulus. The output of the waveguide can be collimated bya collimator 550 located in the center of the annulus. Simulatedtransverse intensity profiles of the collimated annular and Gaussianbeams are shown in an illustration of FIG. 5B. Collimated annular andGaussian beams can be focused onto the sample using one or more lens,such as a GRIN lens 560. In addition to focusing two or more beams, theGRIN lens 560 can be configured to intentionally generate chromaticaberration, which can extend the axial focus further (as shown in anillustration of

FIG. 5C), and to compensate the aberrations induced by the transparentouter sheath 570. The electro-magnetic radiation (e.g., light) can bedirected to the artery wall by a deflector 580.

FIG. 6 shows a schematic diagram of an imaging system for generatingμOCT images according to an exemplary embodiment of the presentdisclosure. As provided in the exemplary embodiment of FIG. 6, an outputof a source 600 providing electro-magnetic radiation(s) (e.g., lightradiation) can be linearly polarized by a linear polarizer 602, andsplit into two or more beams by a beam splitter 604. At least one of thebeams can be redirected to an input port of a switch 606.

At least one of outputs of the switch 606 can be transmitted through abeam splitter 610, and coupled into a first light/electro-magneticradiation guide 612. Another other of the outputs of the switch 606 canbe attenuated by an attenuator 614, guided by a secondlight/electro-magnetic radiation guide 616 to a third beam splitter 618,and redirected to a reference reflector 620 through an attenuator 622, athird light/electro-magnetic radiation guide 624 and a dispersioncompensation arrangement 626. An output of the light guide 612 can beconnected to Bessel illumination and Bessel detection channel of acatheter 628.

As shown in FIG. 6, a further one of the outputs of the beam splitter604 can be redirected to input port of a second three-port switch 630.One of the outputs of the switch 630 can be transmitted through a beamsplitter 632, and coupled into a fourth light/electro-magnetic radiationguide 634. Another one of the outputs of the switch 630 can beattenuated by an attenuator 635 guided by a fifth light guide 636 to afourth beam splitter 638, and redirected to a reference reflector 640through an attenuator 642, a fifth light guide 644 and a seconddispersion compensation arrangement 646. The output of the light guide634 can be connected to a Gaussian illumination and Gaussian detectionchannel of the catheter 628.

When the state of the switch 606 is 1, and the state of switch 630 is 2,e.g., only the light/electro-magnetic radiation guide 612 can beilluminated so that the sample is illuminated by the Bessel illuminationchannel (see Table 1 of FIG. 6). The back-scattered light from thesample can picked up by both, some or all of the Bessel and Gaussiandetection channels of the catheter 628 (see Table 1 of FIG. 6). Theportion of electro-magnetic radiation/light picked up by the Besseldetection channel can be guided by the first electro-magneticradiation/light guide 612 to the beam splitter 610, where suchradiation/light can be combined and interfered with the light from thereference reflector 620.

Further, as illustrated in FIG. 6, at least part of the interferencesignal can be directed by the beam splitter 610 to a pinhole 648. Anoutput of the pinhole 648 can be collimated and split by a polarizingbeam splitter 650. One of outputs of the polarizing beam splitters 650can be transmitted through a half wave plate 652, and detected by aspectrometer 654. Another of the outputs of the polarizing beamsplitters 650 can be detected by a second spectrometer 656. A portion ofthe electro-magnetic radiation/light picked up by the Gaussian detectionchannel can be guided by the light guide 634 to the beam splitter 632,where it is combined and interfered with the light from the referencereflector 640. At least part of the interference signal can be directedby the beam splitter 632 to a pinhole 658. An output of the pinhole 658can be collimated and split by a polarizing beam splitter 660. At leastone of outputs of the polarizing beam splitters 660 can be transmittedthrough a half wave plate 662, and detected by a third spectrometer 664.

Another of the outputs of the polarizing beam splitters 660 can bedetected by a fourth spectrometer 666.

When the state of the switch 606 is 2 and the state of the switch 630 is1, e.g., only the fourth electro-magnetic radiation/light guide 634 canbe illuminated, so that the sample is illuminated by Gaussianillumination channel (shown in Table 1 of FIG. 6). The back-scatteredelectro-magnetic radiation/light from the sample can be picked up byboth Bessel and Gaussian detection channels of the catheter 628 (shownin Table 1 of FIG. 6). At least one portion of the electro-magneticradiation/light picked up by the Bessel detection channel is guided bythe electro-magnetic radiation/light guide 612 to the beam splitter 610,where it can be combined and interfered with the light from thereference reflector 620. At least part of the interference signal can bedirected by the beam splitter 610 to a pinhole 648. An output of thepinhole 648 can be collimated and split by a polarizing beam splitter650. At least one of outputs of the polarizing beam splitters 650 can betransmitted through a half wave plate 652, and detected by aspectrometer 654. Another of the outputs of the polarizing beamsplitters 650 can be detected by a second spectrometer 656.

The portion of light picked up by the Gaussian detection channel isguided by the electro-magnetic radiation/light guide 634 to the beamsplitter 632, where it is combined and interfere with thelight/radiation from the reference reflector 640. At least part of theinterference signal can be directed by the beam splitter 632 to apinhole 658. The output of pinhole 658 is collimated and split by apolarizing beam splitter 660. At least one of the two outputs of thepolarizing beam splitters 660 can be transmitted through a half waveplate 662, and detected by a third spectrometer 664. Another of theoutputs of the polarizing beam splitters 660 can be detected by a fourthspectrometer 666.

Such exemplary polarization-diverse detection scheme/configuration shownin FIG. 6 implemented by the combination of the polarizing beam splitter650, the half wave plate 652 and the spectrometers 654, 656, and/or acombination of the polarizing beam splitter 660, the half wave plate 662and the spectrometers 664, 666 can reduce and/or eliminate artifactsassociated with tissue or optical fiber birefringence. The exemplaryembodiment of the μOCT catheter system according the present disclosureillustrated in FIG. 6 can contain multiple waveguides that can, e.g.,independently transmit and/or receive light/radiation from the catheterto waveguides 612 and 632. The detected signal can be digitized andtransferred by a computer 668 via an image acquisition board 670. Datacan be digitally displayed on or via a monitor 672, and/or stored in astorage device 674.

According the present disclosure, the μOCT detection technology can beimplemented using, in one exemplary embodiment, a time domain OCT(TD-OCT) system, in another exemplary embodiment, a spectral-domain(SD-OCT) system, and, in yet another exemplary embodiment, an opticalfrequency domain interferometry (OFDI) system. Complex images and/orreal images from the different transfer function illumination anddetection configurations can be acquired using the exemplary embodimentof the imaging system according to the present disclosure. In oneexemplary embodiment, such exemplary images can be filtered andrecombined to generate a new image with an improved quality and a CTFthat more closely approximates the diffraction limited CTF. Theexemplary images with different transfer functions can be filtered orrecombined incoherently and/or coherently to generate a new image with aCTF procedure/technique that more closely approximates the diffractionlimited CTF procedure/technique.

FIG. 7 shows another exemplary embodiment of distal optics configurationof a

OCT catheter according to the present disclosure for generating adiffraction-limited CTF and an axial focus range (e.g., depth-of-focus)that can be more than, e.g., approximately 10 times longer than thediffraction-limited depth-of-focus.

For example, an output of a waveguide 700 can be collimated by acollimator 710. Indeed, the waveguide 700 can be routed through theannular beam and is collimated Gaussian beam will be routed through thecenter of the annulus. The collimated light can be transformed into anannular beam through two or more axicons, such as, e.g., GRIN axicons720, 730. A separate waveguide 740 can be routed through a center of theannulus. An output of the waveguide 740 can be collimated by acollimator 750 located in the center of the annulus. The collimatedannular and Gaussian beams can be focused onto the sample using one ormore lens(es) 760, which can be, e.g., one or more GRIN lenses. Inaddition to focusing the beams, the GRIN lens 760 can be configuredand/or structured to intentionally generate chromatic aberration(s),which can extend the axial focus further and compensate for theaberrations induced by a transparent outer sheath. The light/radiationcan be directed to the artery wall by a deflector 770.

FIG. 8 shows another exemplary embodiment of the distal opticsconfiguration of the OCT catheter according to the present disclosure.Such exemplary configuration can be used to generate adiffraction-limited CTF and depth of focus that is, e.g., more than 10times longer than the diffraction-limited depth-of-focus. An output of awaveguide 800 can be collimated by a collimator 810. A pupil aperturecreated by the collimator 810 can be split into two or more beams, i.e.,central circular beam(s) and an annular beam. One or more lenses 820,such as an objective lens, achromat lens, aplanat lens, or GRIN lens,that has an aperture substantially the similar as or identical to acentral zone can focus a low NA Gaussian beam into the tissue or thesample.

The annular beam can be transmitted through a spacer 830, and focusedinto the sample by an annular axicon lens 840 with an aperture that issubstantially similar or identical to the annular beam. The beams can bedirected to the sample by a deflector 850. There can be four imagesgenerated from four channels, e.g., central illumination/centraldetection, central illumination/annular detection, annularillumination/annular detection, annular illumination/central detection.The optical pathlength of the lens 820 can be configured to be differentfrom that of the spacer 830 so that each of, e.g., four images generatedcan be pathlength encoded. In this exemplary embodiment, the differentimages can be detected, and their CTF can be combined as per theexemplary methods and/or procedures described herein.

FIG. 9 shows another exemplary embodiment of the distal opticsconfiguration of the OCT catheter system according to the presentdisclosure, which can be used for generating a diffraction-limited CTFand a depth of focus that is longer than the diffraction-limiteddepth-of-focus. For example, as illustrated in FIG. 9, the output of awaveguide 900 can be collimated by a collimator 910. A pupil aperturecreated by the collimator 910 can be split into two or more zones by acircular glass window 920 positioned at the center of the objective lensaperture, e.g., (i) a central circular zone that is transmitted throughthe circular glass window 920, and (ii) an annular zone. The centralcircular beam can be focused as a low NA Gaussian beam into the tissueand/or sample, and the annular beam can be focused into a Bessel beamfocus in the tissue by the lens 930. A glass window can have a higherrefractive index than air, and the thickness of the window can be sochosen such that the light/radiation field that undergoes differentchannel can be path-length separated and/or encoded. In each A line,there can be three or more segments of signal coming from the (e.g., 4)channels: central illumination/central detection, centralillumination/annular detection, annular illumination/annular detection,annular illumination/central detection.

FIG. 10 shows a further exemplary embodiment of the distal opticsconfiguration of the OCT catheter system for generating adiffraction-limited CTF and a depth of focus that can be longer than thediffraction-limited depth-of-focus. An output of a waveguide 1000 can becollimated by a collimator 1010. A pupil aperture created by thecollimator 1010 can be split into a number of concentric zones 1020,1030, 1040. A multifocal lens, such as, e.g., a GRIN lens, can be usedso that the beam in each zone can be focused to a different axial focalposition. The scattered light/radiation from each zone can be opticalpathlength-encoded so that such scattered beams do not interfere witheach other. In this exemplary embodiment, the different images can bedetected, and their CTF combined pursuant to the exemplary methods andprocedures described herein.

FIG. 11 shows yet another exemplary embodiment of the distal opticsconfiguration of the OCT catheter system for generating adiffraction-limited CTF and an axial focus range (e.g., depth-of-focus)that is longer than the diffraction-limited depth-of-focus. For example,an output of a point object 1100 can be transformed by a mirror tunneldevice 1110 to multiple orders of light/radiation beams, e.g., zerothorder beam 1120, −1st order beam 1130, and −2nd order beam 1140, etc.When a focusing device 1150 is employed so that most or all the order ofrays are focused at the same focal position in the sample, each order ofrays can contain a unique band of spatial frequency of theillumination/detection CTF of the focusing device. These orders can, inyet another exemplary embodiment, be path length-encoded so that imagesgenerated therein can be detected, and their CTF combined using thedifferent images corresponding to the different orders as per theexemplary CTF combination methods and/or procedures described herein.

FIG. 12 shows another exemplary embodiment of the distal opticsconfiguration of the OCT catheter system according to the presentdisclosure for generating a diffraction-limited CTF and a depth of focusthat is longer than the diffraction-limited depth-of-focus. Asillustrated in FIG. 12, an output of a waveguide 1200 can be focused bya half ball lens 1210. A planar surface of the half ball lens 1210 canhave a binary phase pattern 1220. In one further exemplary embodiment,the depth of the pattern can be configured to produce a small phaseshift, e.g., such as a pattern depth of 198 nm en phase shift at 850nm). In another exemplary embodiment, the top surface can be coated witha reflecting coating, such as Au, and a bottom surface can be coatedwith the same and/or another coating such as Al, with the final phaseshift being given by a curve 1300 shown in a graph of FIG. 13, whichillustrates an optical phase length difference of the glass mask (e.g.,no metal coating) and a total phase shift (e.g., mask+coating).

A curve 1310 and a curve 1320 of the graph of FIG. 13 can have awavelength-dependent phase change of the p-polarized light uponreflection at BK7-Al and BK7-Au, respectively, with an incident angle of45 degrees. The curve 1330 can be the wavelength dependent phase shiftof the light caused by, e.g., 198 nm height difference upon 45 degreereflection at BK7-air interface. A binary phase mask can be optimized toproduce an extended axial focus (as shown in an illustration of FIG. 14b) compared with the diffraction limited axial focus (as shown in anillustration of FIG. 14 a). The light/radiation transmitted from thesurfaces with different phase shifts can generate different transferfunctions, which can be detected and combined to create a new image witha different CTF pursuant to the exemplary methods and/or proceduresdescribed herein.

FIG. 15A shows a side-cut-away view of a diagram of another exemplaryembodiment of the distal optics configuration of the OCT catheter systemfor generating a diffraction-limited CTF and an depth of focus longerthan the diffraction-limited depth-of-focus. For example, the system ofFIG. 15A generates the results by a factor of, e.g., approximately 2, 5,10, 20, 50, 100, etc. An output of a waveguide 1500 can be collimated byone or more lens(es) 1510. The collimated beam can be spatiallymodulated by a phase doublet 1520, which can include a positive phaseplate and a negative phase plate with the same or similar phase pattern.By matching Abbe number of the positive phase plate and the negativephase plate, the wavelength dependent phase error can be canceled orreduced. FIG. 15B shows an exemplary graph of transverse phase profilesof an exemplary mask (e.g., BK7-SNPH2 phase doublet mask) illustrated inFIG. 15A For example, by choosing Ohara S-NPH2 (Vd =18.896912, Nd=1.922860) and Schott BK7 (Vd =64.167336, Nd =1.5168), with depth 7.2554um and 13.4668 um respectively, the phase profile is shown in FIG. 15B.The spatially modulated beam can be focused into an extended axial focusby an objective lens 1530.

FIG. 16 shows still another exemplary embodiment of the distal opticsconfiguration of the OCT catheter system for generating adiffraction-limited CTF and depth of focus according to the presentdisclosure that is longer than the diffraction-limited depth-of-focus,by a factor of preferably approximately 2, 5, 10, 20, 50, 100, etc. . Anoutput of a light source 1600 can be split by a beam splitter 1610. Thebeam aperture of at least one of the outputs of the beam splitter can besplit or separated by a rod mirror 1620 into two or more regions. Forexample, the rod mirror 1620 can redirect the central part of the beamto a reference reflector 1630 through an objective lens 1640. Theannular beam can be focused into the sample by a second objective lens1660 that can be substantially similar or identical to one or morelens(es) 1640 into a Bessel focus featured with extended axial focus andsuper-resolution in transverse direction (as shown in the exemplary μOCTimages of FIG. 18D). The light back-scattered from the sample iscombined with the light reflected from the reference reflector throughthe rod mirror at a pinhole 1660. The output of the pinhole 1660 isdetected by a spectrometer 1670. The objective lens 1650 is configuredto intentionally generate chromatic aberration and spherical aberration,which extend the axial focus further (as shown in the exemplary μOCTimages of FIGS. 18C and 18D). FIG. 18A shows an exemplary μOCT image ofa coronary plaque showing multiple leukocytes (arrows). In addition,FIG. 18B shows an exemplary μOCT image of a coronary plaque illustratingmultiple leukocytes (arrows) of two different cell types, one smallercell with scant cytoplasm, consistent with a lymphocyte (L) and another,larger cell with a highly scattering cytoplasm, indicative of a monocyte(M).

Indeed, FIG. 18A illustrates an exemplary μOCT image of a coronaryplaque showing multiple leukocytes 1800 which has been generated usingthe exemplary embodiment(s) of the methods, systems and apparatusaccording to the present disclosure. FIG. 18B illustrates an exemplaryμOCT image of a coronary plaque showing multiple leukocytes of twodifferent cell types, one smaller cell 1810 with scant cytoplasm,consistent with a lymphocyte and another, larger cell 1820 with a highlyscattering cytoplasm, suggestive of a monocyte. FIG. 18C illustrates anexemplary μOCT image of a coronary plaque showing a cell 1830 with anindented, bean-shaped nucleus characteristic of a monocyte. FIG. 18Dillustrates an exemplary μOCT image of a coronary plaque showing aleukocyte 1840 with a multi-lobed nucleus, suggestive of a neutrophilattached to the endothelial surface. FIG. 18E illustrates an exemplaryμOCT image of a coronary plaque showing multiple leukocytes 1850,tethered to the endothelial surface by pseudopodia 1860. FIG. 18Fillustrates an exemplary μOCT image of a coronary plaque showing cells1870 with the morphology of monocytes in this cross-section and insettransmigrating through the endothelium 1880. Further, FIG. 18Gillustrates an exemplary μOCT image of multiple leukocytes 1890distributed on the endothelial surface.

FIG. 19A-19E show exemplary images which have been generated using theexemplary embodiment(s) of the methods, systems and apparatus accordingto the present disclosure. For example FIG. 19A illustrates an exemplaryμOCT image of platelets 1900 (P) adjacent to a leukocyte characteristicof a neutrophil 1910 (N), which is also attached to a small platelet1920 (yellow arrow). FIG. 19B illustrates an exemplary μOCT image offibrin 1930 (F) which is visible as linear strands bridging a gap in thecoronary artery wall. FIG. 19C illustrates an exemplary μOCT image of acluster of leukocytes 1940 (L), adherent to the fibrin in an adjacentsite to FIG. 19B. FIG. 19D illustrates an exemplary μOCT image of Fibrinthrombus 1950 (T) with multiple, entrapped leukocytes. FIG. 19E an μOCTimage of a more advanced thrombus 1960 (T) showing a leukocyte 1970(arrow) and fibrin strands 1980 (inset, F).

Figures 20A-20D show further exemplary images which have been generatedusing The exemplary embodiments(s) of the methods, systems and apparatusaccording to the present Disclosure. For example, Figure 20A illustratesa cross-sectional exemplary μOCT image of endothelial cells 2000 inculture. Figure 20B shows an en face exemplary μOCT image of endothelialcells 2010 in culture. Figure 20C illustrates an exemplary μOCT image ofnative swine coronary artery cross-section 2020l Figure 20D shows athree-dimensional rendering of the swine coronary artery, demonstratingendothelial “pavementing” 2030.

FIGS. 21A and 21B show further exemplary images which have beengenerated using the exemplary embodiment(s) of the methods, systems andapparatus according to the present disclosure. FIG. 21A shows anexemplary μOCT image of microcalcifications which are seen as brightdensities within the μOCT image of the fibrous cap 2100. FIG. 21Billustrates an exemplary μOCT image of microcalcifications which areseen as purple densities on the corresponding histology 2110.

Further, FIGS. 22A-22C illustrate further exemplary images which havebeen generated using the exemplary embodiment(s) of the methods, systemsand apparatus according to the present disclosure. For example, FIG. 22Ashows an exemplary μOCT image of a large calcium nodule, demonstratingdisrupted intima/endothelium 2200. FIG. 22B shows an expanded view of anexemplary region enclosed by the red box shows microscopic tissuestrands, consistent with fibrin 2210, adjoining the unprotected calcium2220 to the opposing detached intima. FIG. 22C shows a correspondinghistology illustrating fibrin 2230 and denuded calcific surface 2240.

In addition, FIGS. 23A-26C illustrate further exemplary images whichhave been generated using the exemplary embodiment(s) of the methods,systems and apparatus according to the present disclosure. For example,FIG. 23A shows an exemplary μOCT image of a large necrotic core 2300fibroatheroma, demonstrating thick cholesterol crystals 2310,characterized by reflections from their top and bottom surfaces. FIG.23B shows an exemplary μOCT image of thin crystal 2320, piercing the capof another necrotic core plaque 2330, shown in more detail in the inset.FIG. 24A shows an exemplary μOCT image of many smooth muscle cells 2400appear as low backscattering spindle-shaped cells (inset). FIG. 24Bshows an exemplary μOCT image of smooth muscle cells producing collagenare spindle shaped, have a high backscattering interior 2410 and a“halo” of low backscattering 2420, which can represent the cell body2430 and collagen matrix 2440, respectively (e.g., histology inset).

FIG. 25A shows an exemplary μOCT image of Taxus Liberte (BostonScientific, Natick, Mass.) struts without polymer 2500, with polymerwithout drug 2510, and with polymer with drug 2520. For polymer-coatedstruts, polymer reflection 2530, strut reflection 2540 and multiplereflections 2550 and 2560 can be seen. FIG. 25B shows an exemplary μOCTimage of a cadaver coronary specimen with an implanted BMS 2570 showsstruts devoid of polymer, covered by neointima 2580. FIG. 25C shows anexemplary μOCT image of a cadaver coronary specimen with implanted DESstruts 2590 from another cadaver showing polymer overlying the strutreflections 2595 (inset).

In addition, FIG. 26A shows an exemplary μOCT image showing tissue 2600has separated the polymer 2610 off of the stent strut 2620 and thepolymer has fractured 2630. FIG. 26B shows an exemplary μOCT imageshowing superficial leukocyte cluster 2640 and adjacent attachedleukocytes 2650 overlying the site of the polymer fracture 2660. FIG.26C shows an exemplary μOCT image showing inflammation 2670 at the edgeof a strut 2680 from another patient. FIG. 26D shows an exemplary μOCTimage showing uncovered strut 2690, completely devoid of overlyingendothelium.

In still another exemplary embodiment of the present disclosure, theoptical elements for the exemplary μOCT system/probe can be fabricatedby irradiating a photopolymer with a tightly focused beam, whoseposition can be controlled in three-dimensions with nm-level precision.The photopolymer can respond to a variable refractive index that can beproportional to an optical energy deposited, facilitating a miniature,solid volume to implement complex optical functionality. (See, e.g.,Sullivan A C, Grabowski M W and McLeod R R, “Three-dimensionaldirect-write lithography into photopolymer”, Applied Optics 2007; 46:295-301; and Scott T F, Kowalski B A, Sullivan A C, Bowman C N andMcLeod R R, “Two-Color Single-Photon Photoinitiation and Photoinhibitionfor Subdiffraction Photolithography”, Science 2009; 324: 913-7; also seeU.S. Patent Publicaton Nos. 2009/0218519 and 2006/0193579).

Such exemplary method and procedure previously generated miniature fibercouplers, tapered waveguides, waveguide arrays, lenses, diffractiveoptical elements, and complex optical assemblies, all within amonolithic, polymer component, for example. This exemplary embodimentfacilitates the exemplary μOCT probe to be a stable, monolithic elementthat can provide the extended focal depth functionality describedherein, than can be incorporated into, e.g., miniaturized μOCT cathetersand endoscopes. One advantage of this exemplary embodiment is that thephotopolymer-derived optical element/arrangement can be made repeatedlywith a high precision, and can be mass-produced at relatively low cost.

FIG. 27A shows a flow diagram of a method for providing data associatedwith at least one portion of at least one sample according to oneexemplary embodiment of the present disclosure. For example, inprocedure 2710, at least one first radiation is forwarded to at leastone portion of the sample through at least one optical arrangement(e.g., as described in various exemplary embodiments herein), and atleast one second radiation is received from the portion which is basedon the first radiation. Based on an interaction between the opticalarrangement and the first radiation and/or the second radiation, theoptical arrangement has a first transfer function. Then, in procedure2720, at least one third radiation is forwarded to the portion throughsuch optical arrangement, and at least one fourth radiation is receivedfrom the portion which is based on the third radiation. Based on aninteraction between this optical arrangement and the third radiationand/or the fourth radiation, the optical arrangement has a secondtransfer function. The first transfer function can be at least partiallydifferent from the second transfer function. Further, in procedure 2730,the data associated with the portion(s) can be generated based on thesecond and fourth radiations.

FIG. 27B shows a flow diagram of the method for providing dataassociated with at least one portion of at least one sample according toanother exemplary embodiment of the present disclosure. For example, inprocedure 2760, at least one first radiation is forwarded to at leastone portion of the sample through at least one first optical arrangement(e.g., as described in various exemplary embodiments herein), and atleast one second radiation is received from the portion which is basedon the first radiation. Based on an interaction between the firstoptical arrangement and the first radiation and/or the second radiation,the first optical arrangement has a first transfer function. Then, inprocedure 2770, at least one third radiation is forwarded to the portionthrough at least one second optical arrangement, and at least one fourthradiation is received from the portion which is based on the thirdradiation. Based on an interaction between the second opticalarrangement and the third radiation and/or the fourth radiation, theoptical arrangement has a second transfer function. The first transferfunction can be at least partially different from the second transferfunction. Further, in procedure 2780, the data associated with theportion(s) can be generated based on the second and fourth radiations.

The foregoing merely illustrates the principles of the presentdisclosure. Various modifications and alterations to the describedembodiments will be apparent to those skilled in the art in view of theteachings herein. For example, more than one of the described exemplaryarrangements, radiations and/or systems can be implemented to implementthe exemplary embodiments of the present disclosure Indeed, thearrangements, systems and methods according to the exemplary embodimentsof the present invention can be used with and/or implement any OCTsystem, OFDI system, SD-OCT system or other imaging systems, and forexample with those described in International Patent ApplicationPCT/US2004/029148 filed Sep. 8, 2004 (which published as InternationalPatent Publication No. WO 2005/047813 on May 26, 2005), U.S. patentapplication Ser. No. 11/266,779 filed Nov. 2, 2005 (which published asU.S. Patent Publication No. 2006/0093276 on May 4, 2006), U.S. patentapplication Ser. No. 10/861,179 filed Jun. 4, 2004, U.S. patentapplication Ser. No. 10/501,276 filed Jul. 9, 2004 (which published asU.S. Patent Publication No. 2005/0018201 on Jan. 27, 2005), U.S. patentapplication Ser. No. 11/445,990 filed Jun. 1, 2006, International PatentApplication PCT/US2007/066017 filed Apr. 5, 2007, and U.S. patentapplication Ser. No. 11/502,330 filed Aug. 9, 2006, the disclosures ofwhich are incorporated by reference herein in their entireties. It willthus be appreciated that those skilled in the art will be able to devisenumerous systems, arrangements and methods which, although notexplicitly shown or described herein, embody the principles of thepresent disclosure and are thus within the spirit and scope of thepresent disclosure. In addition, to the extent that the prior artknowledge has not been explicitly incorporated by reference hereinabove, it is explicitly being incorporated herein in its entirety. Allpublications referenced herein above are incorporated herein byreference in their entireties.

What is claimed is:
 1. An apparatus for providing at least oneelectro-magnetic radiation to at least one sample, comprising: aplurality of wave-guiding arrangements configured to (i) provide the atleast one electro-magnetic radiation along different paths, and (ii) ata point of emission of each of the wave guiding arrangements, cause aphase of each of the at least one electro-magnetic radiation to have apredetermined value; and at least one lens arrangement which isconfigured to receive the at least one electro-magnetic radiation fromthe wave-guiding arrangements, and generate a focus-spot radiation tohave a diameter that is smaller than a diffraction limited spot on or inthe sample.
 2. The apparatus according to claim 1, wherein thewave-guiding arrangements provide the at least one radiation in at leastpartially a circular pattern.
 3. The apparatus according to claim 1,wherein the at least one lens arrangement is configured to cause thefurther focus-spot radiation to have an extended focal depth.
 4. Theapparatus according to claim 1, wherein the diffraction limited spot isa three-dimensional spot.
 5. The apparatus according to claim 1, whereinthe at least one lens arrangement includes a grin lens.
 6. The apparatusaccording to claim 1, wherein at least one of the wave-guidingarrangements is a single-mode wave-guide.
 7. The apparatus according toclaim 1, wherein at least one of the wave-guiding arrangements iscomposed of a photo-polymer.
 8. The apparatus according to claim 1,further comprising a further wave-guiding arrangement is configured toprovide a further electro-magnetic radiation to the sample, wherein theat least one electro-magnetic radiation and the further electro-magneticradiation are provided to at least partially overlapping portions of thesample.
 9. The apparatus according to claim 1, further comprising ahousing which at least partially encloses the wave-guiding arrangements.10. The apparatus according to claim 9, further comprising a sheathenclosing the housing.
 11. The apparatus according to claim 9, furthercomprising a control arrangement which is configured to at least one ofrotate or translate the housing.
 12. The apparatus according to claim 1,wherein the at least one lens arrangement includes at least one opticalelement which is at least one formed by or subjected to a photopolymerprocessing.
 13. The apparatus according to claim 12, wherein thephotopolymer processing includes irradiating a photopolymer so as toform the at least one optical element.
 14. A probe for providing atleast one electro-magnetic radiation to at least one sample, comprising:a plurality of wave-guiding arrangements configured to (i) provide theat least one electro-magnetic radiation along different paths, and (ii)at a point of emission of each of the wave guiding arrangements, cause aphase of each electro-magnetic radiations to have a predetermined value;and at least one lens arrangement which is configured to receive the atleast one electro-magnetic radiation from the wave-guiding arrangements,and generate a focus-spot radiation to have a diameter that is smallerthan a diffraction limited spot on or in the sample.
 15. A system forimaging at least one sample, comprising: a probe comprising a pluralityof wave-guiding arrangements configured to (i) provide at least oneelectro-magnetic radiation to the at least one sample along differentpaths, and (ii) at a point of emission of each of the wave guidingarrangements, cause a phase of each electro-magnetic radiations to havea predetermined value; an interferometric arrangement provided incommunication with the probe; and at least one lens arrangement which isconfigured to receive the at least one electro-magnetic radiation fromthe wave-guiding arrangements, and generate a focus-spot radiation tohave a diameter that is smaller than a diffraction limited spot on or inthe sample.
 16. The system according to claim 15, wherein theinterferometric arrangement is part of the probe.